Driving a Car Increases the Risk

“Since previous scientific findings have shown an association between one-sided exposure to ultraviolet light (UV) and an asymmetric facial distribution of sun damage, we would expect that skin cancers also would be more prevalent on the left side of the body in drivers who spend a significant amount of time in their cars,” said Scott Fosko, MD, FAAD, professor and chairman of dermatology at Saint Louis University School of Medicine in St. Louis. “Our initial findings confirm that there is a correlation between more time spent driving and a higher incidence of left-sided skin cancers, especially on sun-exposed areas in men.”

Of the skin cancers that were reviewed, 608 were basal cell carcinomas, 178 were squamous cell carcinomas, 23 were invasive melanomas, 42 were in situ, or non-invasive, melanomas and 64 were miscellaneous cancers. While Dr. Fosko expected the number of basal cell carcinomas to be the highest type of skin cancers reported since they are the most common form and are associated with cumulative sun exposure, he was surprised by the number of non-invasive melanomas that occurred on the left side of the patients studied – 31 of the 42 non-invasive melanomas reported, which accounted for 74 percent.

“Our initial data shows that those individuals under age 70 who consistently spent the most time per week driving a car were more likely to develop left-sided skin cancers,” said Dr. Fosko. “We’re also finding that all drivers who occasionally drive with the windows open had a higher incidence of left-sided skin cancers. Light skin complexion and more driving time also increased the risk for forming skin cancers on the left side. Since there are more cars on the road than ever before, it is likely that this trend will continue.”

Typically, an automobile’s side and rear windows are made from non-laminated glass that is designed to block UVB rays (the sun’s burning rays), but not the deeper penetrating UVA rays.